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2 Sheets-Sheet I.

GRUGIBLB PURNGE.

Patented Aug. 4, 1885.

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(No Model.) A

T. M'GBRIDE, P. B. SMITH & A. J. LENNOX ATTORNEY.

VVITNESSES:I

(Nn Model.) v2 Sheets-#Sheet 2.-

4T. MGBRIDE, F. B.v SMITH & A. J. LENNOX.

GRUGIBLE FURNAGE.

No. 828,876. VPatented Aug. 4, 1885.

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BY mi .(0 'm/ ATTORNEY.

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/ITNESSESz N. PETERS. Phat UNITED STATES .PATENT Ori-TCR.'

THOMAS McRRiDn, FRANK. R. sMiTrLAND ANDREW J. LnNNoX, on ALLE- GHRNY,PA., AssieNoRs To sMiTH, sUTToN a co., oF sAMn PLAGE.

CRUCIBLE-FURNACE.

SPECIFICATION forming part of Letters Patent No. 323,876, dated August4, 1885.

Application filed May 4, 1885. (No model.)

T o all whom it may concern;

Be it known that we,TnoMAs MGBRIDE, FRANK. B. SMITH, and ANDREW J.LENNoX, residing at Allegheny, in the county of Allegheny and State ofPennsylvania, citizens ot' the United States, have invented ordiscovered certain new and useful Improvements in Urucible-Pot Furnaces,of which improvements the following is a specification.

part of this specication, Figure 1 is a transverse sectional elevationof our improved crucible-furnace. Fig. 2 is a top plan view of the same.Fig. 3 is a longitudinal sectional elevation of a portion of thefurnace. .Fig. 4 includes perspective views of a number of bricksemployed in constructing our furnace.

ln the ordinary mode of building Crucible-pot furnaces for melting steelit has been usual to 2o lay the bricks constituting thefront of thefurnace-chamber with a downward slope toward the inside of the chamber.The action of the heat on the wall of a chamber so built tends to drawthe bricks out of positionin the direction 2 5 in which they slope, sothat the wall is liable to rapid destruction, especially as when thebricks spring` or yield a little out of place the furnaceheat works inback of them and between them and the outer wall of the furnace, andthereby 3o hastens the necessity of rebuilding. lt is also true offurnaces of this class that the air and gas intake flues or passagesshould slope downwardly both at top and bottom, for reasons wellunderstood in the art. The present in- 3 5 vention relates to theconstruction of this front furnace-wall, both in its general featuresand in the specific features hereinafter pointed out.

Upon a suitable bed-plate, 1, secured as shown in the supporting orshell walls A, are

4o built up the usual piers, 2", and side walls, 3, of

the melting-chamber B in the ordinary manner of constructing such parts,thereby forming continuations of the air and gas iiues 4. The bottom ofthat portion ofthe intake-dues 4 5 formed by the'piers and side walls isformed bya singlebrick, 5, (see Fig. 1,) ofa length and width sufficientto constitute the bottom of each said ilue, and having its top surfaceinwardly inclined in order to impart the desired 5o direction toinfiowing currents of gas and air. The tops of the piers 2 and theabutment. 6,

In the accompanying drawings, which make proj cctin g from one of theside walls, are formed of single bricks 7, 8, and 9, which-slope alittle in the direction of the ends of the heatingchamber, the bricks 7and 8 sloping toward one end and the brick 9 sloping in the oppositedirection. (See Fig. 3.) These piers and the abutment are of such arelative height and the sloping surfaces of the bricks have suchrelationship to each other as to give a slight arch to the course ofbricks supported thereon. The inner adjacent corners of the bricks S and9, forming the tops of the piers 2, are provided with notches orrecesses 10, and the space between them is' bridged across by aspeciallyshaped brick, 11, designed for that purpose, the lower face ofwhich along its middle part is sloped, as shown at 12, to conform to theslope imparted to bottom of the iiue by the wedge-shaped brick 5. rlhelower inside corners of the brick 1l are provided with lugs orprojections 13,-adapted to rest and till the recesses 10 of the bricks 8and 9, and back of these lugs or projections 13 the lower side of thebrick on each side of the slope l2 is cut away and made to conform withand rest upon the adjacent edges of the top bricks, S and 9. The depthof the recesses 10 in the bricks 8 and 9 is such as to drop the innerend of the bridge-brick 11 downward below the tops of the piers at thecenter of the arch sufficiently to bring this central intake-flue to thesame height as that of each side iiue. The space between the right-handpier, 2, in Fig. 3, and the side wall, 3, is bridged over by a brick,14, one edge of which rests upon the pier 2, and the other upon the sidewall, 3. The under surface of this brick is beveled or inclined tocorrespond with the slope or inclination of the arch of the first courseof bricks, but the upper surfacel is practically straight, and thatportion of the under surface which rests upon the side wall is madestraight j to give it a firm bearing upon the side wall. In order thatthis brick may act as a key or filling piece, that. portion, 15, whichprojects within the side wall is given a wedge shape, as clearly shownby dotted lines in Figs. 3 and 4. The space between the abutment 6 andits adjacent pier 2 is bridged over by a brick, 16, one edge of whichrests upon the pier and the other edge upon the abutment. The edges ofIOO the brick differ in thickness by an amount equal or nearly equal tothe slope of the arch through its width, or to the shape of the bricks 7and 8, forming the tops of the abutments and piers, as shown in Fig. 3.Along the middle of the lower face of each of the bricks 14 and 16 asloping groove, 17, is cut, corresponding to the slope of the top facesof the bricks 5, forming the bottoms of the iiues. Alongside ofthe brick16 is placed a brick, 1S, resting partly on the inclined brick 7 of theabutment and partly on the bricks of the side wall, its under faceheilig' correspondingly shaped to fit these different surfaces. Theouter edges of the bricks 14 and 1S are beveled downwardly and inwardly,so as to admit of the insertion outside of correspondingly-beveledkeybricks, 1E) and 20, which tend to hold this layer or course of' bricksecurely in place, and all in a horizontal position, except as they arearched, and also to aid in sustaining the arch. Filling-bricks 21 and22, of suitable shape, are inserted over the middle of each pier, thiscompleting the first course. rlhe bricks of this first course are soconstructed that their upper surface will form a slight arch, as clearlyshown in Fig. 3, but the spring of this arch is very much less th anthat formed by the under surfaces of said bricks. The object of soarching this top surface is to permit of slightly arching the subsequentcourses of bricks, thereby partially relieving' the. trst course of theweight of such subsequent courses. This first course is horizontal, ornearly so, toward the furnace, and is slightly arched in the directionof the length of the furnace or transverse of the bricks on its topsurface; and by the term horizontah77 as regards the arrangement ofthefirst course of brick, I mean that the main longitudinal lines of thebricks composing this course are practically horizontal; but as theeffect of the heat of the furnace-chamber is to draw the bricksinwardly, I make them all, except the keying-bricks, at ends of thecourse, wider at their base ends than at their inner or furnace-chamberends, so as to give an arch in a horizontal plane, (see Figs. 1 and 2,)and thereby render the structure more durable. rlhe remaining courses orlayers of brick are made of bricks 23, each as long as the wall isthick, and the brick of each course being a little longer than those ofthe preceding or next lower course, and having'their inner ends beveled,so as to give in some degree the desired shape to the inside ofthefurnace. rlhese bricks, like those of the first course or layer, havetheir outer ends alittle broader at its base than at the inner orfurnace-chamber end, so as to give an arch in a horizontal plane. Fachend of each layer or course terminates in a keybrick, which, like thekey-bricks ot' the first layer, come into the division or bridge-walls,or in the plane thereof, so as to be out of the destructive effects ofthe intense heat in the meltin g-ch amber.

It is a characteristic feature of the furnace above described that eachbrick composin the sides of the chamber lies in a horizontal. plane inplace of being inclined inwardly as in the old form of furnace, and thatthe bricks which are directly exposed to the .ef-` fects of the heat areall larger in a horizontal plane at their base or outer ends than attheir inn er-furnaee or chamber ends, so as to prevent as far aspossible the inwardly-drawing effects of the heat. The vertical archgiven to the first layer of brick is preferably carried up through allthe bricks above, though in a less degree, so that in effect while allthe bricks in the direction of their length or crosswise of the wall arelaid horizontally and are therefore in the position of greateststability, they are also so constructed and laid that the wall is doublyarched-that is, each layer is arched in a horizontal plane as againstthe inwardly-drawing effect of the heat, and are also arched slightly ina vertical plane, by which the better to resist any and all downwardstrains.

In constructing the furnace, the abutment 6, on one side of the furnace,will project from the division-wall at one end of the furnace, and onthe other side will project from the division-wall at the opposite endof the furnace, and the piers will be correspondingly located. By thisarrangement the abutment and piers on one side of the chamber will belocated opposite the iiues entering the opposite side of the furnace,thereby insuring a circulation of the air and gas in the chamber.

Ve claim herein as our invention- 1. In a melting-furnace, havingoverhanging side walls, the arch forming the bottom or foundation ofsuch wall and the topof the intake-fines composed of a series of brickarranged in horizontal planes, substantially as set forth.

2. A melting-furnace having the arch form ing the top of its intake-nuescomposed of a series of brick arranged iu horizontal planes, said brickhaving their base or outer ends broader than their inner orfurnacechamber ends, whereby an arch in a horizontal plane is formed bysaid series of brick, substantially as set forth.

3. A melting-furnace having the top of each of its intake-titles formedof a single brick, said brick a member of the arch spanning all thetlues on one side of the furnace, substantially as set forth.

et. In a melting-furnace, the arch forming the top of its intake-fines,composed of a series of brick arranged in horizontal lines, incombination with the supporting-piers, the top of each pier being formedof a single brick having its top surface shaped to correspond with theunder surface ofthe arch, and lying in a horizontal plane, substantiallyas set fort-h.

5. In a melting-furnace having the top of its flues formed of a seriesof brick, the bricks 8 and 9 forming the tops of the piers on each IOOIOS

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side ofthe central flue, and having notches or recesses at their innercorner, in combination with the brick 11, provided With thelugs orprojections 13, adapted to t Within 4said recesses, substantially as setforth.

6. In a melting-furnace having the top of its fines formed of a seriesof brick7 the coinbinaton of the bricks 8 and 9, forming` the tops ofthe piers, and the brick 1l, said bricks being so constructed that theinner end of the brick l1 is dropped down sufficiently to bring the topof the central to the same height as the side fiues7 substantially asset forth.

7. In a melting-furnace, a series of brick constituting the top layer orfinishing course so shaped and arranged as to form an arch in Intestimony whereof We have hereunto set 2 5 our hands.

THOMAS MCBRIDE. FRANK. B. SMITH. ANDREW J. LENNOX. Witnesses:

DARWIN S. WoLcorT, R. H. WHrT'rLnsEY.

